Add the polling timeout example and update the catalog.

2 files changed, 115 insertions, 0 deletions

diff --git a/testsuite/systemtap.examples/profiling/timeout.meta b/testsuite/systemtap.examples/profiling/timeout.meta
new file mode 100644
index 00000000..aa683c0a
--- /dev/null
+++ b/testsuite/systemtap.examples/profiling/timeout.meta
@@ -0,0 +1,13 @@
+title: Show Processes Doing Polling Operations
+name: timeout.stp
+version: 1.0
+author: Uli Drepper and William Cohen
+keywords: profiling
+subsystem: kernel
+status: production
+exit: user-controlled
+output: sorted-list
+scope: system-wide
+description: The timeout.stp script is based on a blog entry (http://udrepper.livejournal.com/19041.html) mentioning a need for a tool to help developers find applications that are polling. The timeout.stp script monitors systemcall used for polling and records the systemcalls that timed out rather than returned because some action occurred. The script updates the screen once a second with the top twenty processes.
+test_check: stap -p4 timeout.stp
+test_installcheck: stap timeout.stp -c "sleep 1"
diff --git a/testsuite/systemtap.examples/profiling/timeout.stp b/testsuite/systemtap.examples/profiling/timeout.stp
new file mode 100644
index 00000000..48d6d21d
--- /dev/null
+++ b/testsuite/systemtap.examples/profiling/timeout.stp
@@ -0,0 +1,102 @@
+#! /usr/bin/env stap
+# Copyright (C) 2009 Red Hat, Inc.
+# Written by Ulrich Drepper <drepper@redhat.com>
+# Modified by William Cohen <wcohen@redhat.com>
+
+global process, timeout_count, to
+global poll_timeout, epoll_timeout, select_timeout, itimer_timeout
+global nanosleep_timeout, futex_timeout, signal_timeout
+
+probe syscall.poll, syscall.epoll_wait {
+  if (timeout) to[pid()]=timeout
+}
+
+probe syscall.poll.return {
+  p = pid()
+  if ($return == 0 && to[p] > 0 ) {
+    poll_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+    delete to[p]
+  }
+}
+
+probe syscall.epoll_wait.return {
+  p = pid()
+  if ($return == 0 && to[p] > 0 ) {
+    epoll_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+    delete to[p]
+  }
+}
+
+probe syscall.select.return {
+  if ($return == 0) {
+    p = pid()
+    select_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+  }
+}
+
+probe syscall.futex.return {
+  if (errno_str($return) == "ETIMEDOUT") {
+    p = pid()
+    futex_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+  }
+}
+
+probe syscall.nanosleep.return {
+  if ($return == 0) {
+    p = pid()
+    nanosleep_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+  }
+}
+
+probe kernel.function("it_real_fn") {
+  p = pid()
+  itimer_timeout[p]++
+  timeout_count[p]++
+  process[p] = execname()
+}
+
+probe syscall.rt_sigtimedwait.return {
+  if (errno_str($return) == "EAGAIN") {
+    p = pid()
+    signal_timeout[p]++
+    timeout_count[p]++
+    process[p] = execname()
+  }
+}
+
+probe syscall.exit {
+  p = pid()
+  if (p in process) {
+    delete process[p]
+    delete timeout_count[p]
+    delete poll_timeout[p]
+    delete epoll_timeout[p]
+    delete select_timeout[p]
+    delete itimer_timeout[p]
+    delete futex_timeout[p]
+    delete nanosleep_timeout[p]
+    delete signal_timeout[p]
+  }
+}
+
+probe timer.s(1) {
+  printf("\033[2J\033[1;1H") /* clear screen */
+  printf ("  uid |   poll  select   epoll  itimer   futex nanosle  signal| process\n")
+  foreach (p in timeout_count- limit 20) {
+     printf ("%5d |%7d %7d %7d %7d %7d %7d %7d| %-.38s\n", p,
+              poll_timeout[p], select_timeout[p],
+              epoll_timeout[p], itimer_timeout[p],
+              futex_timeout[p], nanosleep_timeout[p],
+              signal_timeout[p], process[p])
+  }
+}